A wireless tag stores information therein by an electromagnetic method. The wireless tag is identified by reading the information stored in the wireless tag using a reader.
Initialization of the wireless tag means that the identification information is written in the wireless tag.
If a large number of wireless tags need to be initialized, a wireless tag initialization device is used. The wireless tag initialization device continuously initializes plural wireless tags supported on amount using one reader and writer. Therefore, a problem of how to specify a wireless tag to be initialized needs to be addressed.
In a wireless tag initialization device of the related art, the intensity of response waves from wireless tags is measured to specify a tag to be initialized.
However, some wireless tags output response waves with a predetermined intensity regardless of the intensity of received power. As a result, such a type of wireless tag cannot be specified as a tag to be initialized using methods of the related art.